Fidei donum. [Encycliek 21 april 1957].

MLA

Pius. Fidei Donum. [encycliek 21 April 1957]. Fribourg: Ed. St-Paul, 1958.

APA

Pius, P. (1958). Fidei donum. [Encycliek 21 april 1957]. Fribourg: Ed. St-Paul.

Chicago

Pius Fidei Donum. [encycliek 21 April 1957]. Fribourg: Ed. St-Paul, 1958.